How to use the af-webpack/getUserConfig function in af-webpack

const { cwd = process.cwd(), entry } = opts;

  const babel = resolve(__dirname, './babel.js');
  const paths = getPaths(cwd);

  // register babel for config files
  registerBabel(babel, {
    cwd,
    configOnly: true,
  });

  // get user config
  let config = null;
  let returnedWatchConfig = null;
  try {
    const configObj = getConfig({ cwd });
    ({ config } = configObj);
    returnedWatchConfig = configObj.watch;
    debug(`user config: ${JSON.stringify(config)}`);
  } catch (e) {
    console.error(chalk.red(e.message));
    debug('Get .webpackrc config failed, watch config and reload');

    // 监听配置项变更，然后重新执行 dev 逻辑
    watchConfigs().on('all', (event, path) => {
      debug(`[${event}] ${path}, unwatch and reload`);
      unwatchConfigs();
      runDev(opts);
    });
    return;
  }